Description:
This tree is 40-90' tall at maturity, forming a trunk about 1½-4'
across and a globoid to ovoid crown that is often irregularly shaped.
On thin rocky soil, dwarf specimens of this tree may develop that are
only 15-30' tall, but they are usually too weak to develop acorns. For
mature trees, trunk bark is light gray to gray, thin, flaky, and
irregularly fissured. Sometimes trunk bark develops narrow scales,
but deep vertical furrows are absent. Branch bark is light gray and
more smooth, while twigs are yellowish brown, brown, or reddish brown,
and glabrous with scattered white lenticels. Young shoots are light
green, glabrous or pubescent, and terete. Alternate leaves occur along
the twigs and young shoots. These leaves are 2-7" long and ¾-3½"
across; they are oblong-oblanceolate to broadly oblong-oblanceolate or
oblong-elliptic to broadly oblong-elliptic in shape. Along their
margins, individual leaves are pinnatifid with 7-15 pairs of shallow
lobes that are rounded or tooth-like (usually the latter). Tooth-like
lobes curve away from the leaf base and their tips are either pointed
or blunt. The leaf surface along the margins is either flat or
wavy (up and down). The lateral veins of each leaf are nearly parallel
to each other; they equal the number of lobes along the margin. The
upper surface of mature leaves is dark green and glabrous, while the
lower surface
is either pale grayish green or white and more or less covered with
fine stellate hairs. Immature leaves, in contrast, are yellowish green
on both the upper and lower surfaces. The petioles are light green to
yellow (often the
latter), glabrous, and up to 1½" long. Here is a photo of
Leafy
Branches.
Chinkapin Oak is monoecious,
producing separate male (staminate) and female (pistillate) flowers on
the same tree. Male flowers are produced in drooping greenish yellow
catkins (2-4" long) from twigs of the preceding year. Individual male
flowers are
less than 1/8" (3 mm.) across, consisting of an irregularly lobed hairy
calyx
and several stamens. Female flowers are produced individually or in
very short spikes (with 2-3 female flowers) from the tips of the
current year's twigs. Individual female flowers are about 1/8" (3 mm.)
across
and reddish green, consisting of a hairy ovoid calyx that surrounds an
ovary with 3 stigmata at its apex. The flowers are cross-pollinated by
the wind during mid- to late spring. Some female flowers become
aborted, while others develop into acorns during the summer. At
maturity during the autumn, these acorns are about ¾" long and ovoid in
shape. Each mature acorn has a pale gray cap that is slightly
tuberculate (bumpy or warty); it extends downward to about one-third
the length of the acorn. The nut of a mature acorn is glabrous and
brown to black; its interior contains white meat that is mildly sweet
and edible. The root system consists of a taproot and spreading lateral
roots. During autumn, the deciduous leaves become dull red or brown; a
few leaves may persist on a tree during the winter.
Cultivation:
The preference is full sun, mesic to dry-mesic conditions, and a mildly
acidic to alkaline soil containing loam, silt-loam, clay-loam, or
glacial till. Seedlings and young saplings have greater tolerance of
shade than mature trees.
Range
& Habitat: The native
Chinkapin Oak is occasional throughout Illinois (see
Distribution
Map).
Habitats include mesic to upland woodlands, rocky upland
woodlands, thinly wooded bluffs, wooded slopes, savannas, limestone
glades, and woodland borders along fields, roads, and parking
lots. This tree is often associated with mineral-rich glacial moraines
and rocky
areas where limestone underlies the soil surface.
Faunal
Associations: In Illinois and neighboring areas of the
Midwest, the
caterpillars of several butterflies and skippers eat the foliage of
Chinkapin Oak and other oaks (
Quercus
spp.):
Calycopis
cecrops
(Red-Banded Hairstreak),
Erynnis
brizo (Sleepy Duskywing),
Erynnis
juvenalis (Juvenal's Duskywing),
Fixsonia favonius ontario
(Northern
Hairstreak),
Parrhasius
m-album (White-M Hairstreak),
Satyrium calanus
falacer (Banded Hairstreak), and
Satyrium liparops strigosum
(Striped
Hairstreak). Moth caterpillars also eat the foliage of oaks, including
such species as
Acronicta
increta (Southern Oak Dagger Moth),
Antherea
polyphemus (Polyphemus Moth),
Bucculatrix ainsliella
(Oak Skeletonizer
Moth),
Hyphantria cunea
(Fall Webworm), and
Symmerista
canicosta
(Red-Humped Oakworm). In contrast, the moth caterpillars
Paranthrene
asilipennis (Oak Stump Borer Moth) and
Paranthrene simulans
(Hornet
Clearwing) bore through the wood, while the caterpillars of
Melissopus
latiferreanus (Filbert Worm) and
Valentina glandulella
(Acorn Moth)
feed on the meat of acorns. See the
Moth Table for a
more complete list
of species that feed on oaks.
Many aphids, leafhoppers, and treehoppers
feed on the tissues and juices of oaks (see
Homoptera Table).
Chinkapin
Oak is a preferred host of the leafhopper
Eratoneura impar
(syn.
Erythroneura impar).
Other insect feeders include
Corythucha
arcuata
(Oak Lace Bug), the plant bugs
Ceratocapsus
modestus and
Plagiognathus
guttulosus, the stink bug
Pseudoxenetus regalis,
several leaf beetles
(
Bassareus croceipennis,
Lupraea picta,
Metachroma spp.,
Pachybrachis
spp., &
Paria
opacicollis), larvae of the leaf-folding weevils
Attelabus bipustulatus
and
Homoeolabus analis,
the
larvae of many
wood-boring beetles (see
Wood-Boring Beetle Table),
and the larvae of
several gall wasps (Cynipidae). Among vertebrate animals, the palatable
acorns of Chinkapin Oak are a source of food to such birds as the Wild
Turkey, Ring-Necked Pheasant, Bobwhite Quail, Red-Headed
Woodpecker, Crow, Blue Jay, Tufted Titmouse, Carolina Chickadee,
and White-Breasted Nuthatch. The acorns are also eaten by such mammals
as the Black Bear, Raccoon, Fox Squirrel, Gray Squirrel, Red Squirrel,
Southern Flying Squirrel, Eastern Chipmunk, and White-Footed Mouse.
White-Tailed Deer browse on the twigs and foliage, particularly of
saplings. Older trees of Chinkapin Oak often have cavities that
provide habitat for cavity-nesting birds (e.g., woodpeckers, owls,
& chickadees) and dens for various mammals (e.g., tree
squirrels,
bats, & raccoons).
Photographic
Location: Edge of a wooded area at Weaver Park in Urbana,
Illinois.
Comments:
Across local populations, there is significant variability in the size
and width of leaves, and also the hairiness and color of leaf
undersides. The scientific name of Chinkapin Oak is sometimes spelled
Quercus muehlenbergii.
The common name of this tree is sometimes spelled
Chinquapin Oak, and it is also referred to as Yellow Chestnut Oak. This
tree is one of the 'chestnut oaks' in the white oak group. The common
name of this group derives from the fact that their leaves resemble
those of
Castanea spp. (chestnuts).
Among
Quercus spp.
(oaks) in
Illinois, the acorns of Chinkapin Oak are regarded as less bitter and
more edible than most. The wood of this tree is hard, heavy, strong,
and durable;
it has been used to make cabinets, furniture, containers, and rail
ties. It is also a source of excellent firewood. In addition to
Chinkapin Oak, two other species of chestnut oaks occur in Illinois in
the southern section of the state:
Quercus
prinus (Rock Chestnut Oak)
and
Quercus michauxii
(Swamp Chestnut Oak). Generally, these two
species have wider leaves with more rounded lobes than those of
Chinkapin Oak, and their acorns are larger in size (1" long or more).
However, some overlap in leaf characteristics can occur among these
species, and they may hybridize in areas where their ranges overlap.
Mature trees of Rock Chestnut Oak have deeply furrowed bark, which is
very unlike the thin flaky bark of Chinkapin Oak. Swamp Chestnut Oak
prefers wetter habitats than either Rock Chestnut or Chinkapin Oak.
Sometimes, Chinkapin Oak is considered a variety of
Quercus prinoides prinoides
(Dwarf Chinkapin
Oak), or
Quercus
prinoides acuminata. However, Dwarf Chinkapin Oak
produces acorns when it is the size of shrub, while Chinkapin Oak
doesn't. The leaves of Dwarf Chinkapin Oak are usually smaller in size
and more broad in shape with fewer pairs of lobes (less than 10).